Exercise Reduces Morphine-Induced Hyperalgesia and Antinociceptive Tolerance

Figure 6

Exercise preconditioning did not prevent the development of morphine-induced hyperalgesia in the (a) hot-plate test and (b) tail-flick test. Rats first received 30-minute exercise training for 2 weeks, then morphine 30 mg/kg was injected daily, and behavior tests were performed 1 h before morphine subcutaneous injection.

(a)

(b)